1) THE "BI'AH" OF A NINE-YEAR-OLD BOY
QUESTION: The Mishnah continues to discuss various Halachos that apply to minors who have become physically capable of having relations. The Mishnah teaches that when a nine-year-old boy has relations with an animal, he makes the animal unfit to be offered as a Korban on the Mizbe'ach, and if two valid witnesses see the act, Beis Din stones the animal to death.
The Mishnah earlier (44b) does not mention these Halachos with regard to a three-year-old girl. The Gemara in Sanhedrin (55b), however, explains that these Halachos apply to girls as well. The Gemara explains that the Halachah that a three-year-old girl who has relations with an animal renders the animal unfit to be a Korban is included in the phrase of the Mishnah that if she has forbidden relations with "any one of the Arayos mentioned in the Torah," they are put to death. This includes having relations with animal.
Why does the Mishnah mention the law of bestiality explicitly with regard to a nine-year-old boy and not with regard to a three-year-old girl?
ANSWERS:
(a) TOSFOS in Sanhedrin (55b, DH v'Chayavin) explains that there is another difference between the Mishnah here and the Mishnah earlier, from which we may infer the answer to this question. The Mishnah earlier says that a man who has relations with a married three-year-old girl is Chayav Misah. This teaching seems unnecessary, because the Isur of Eshes Ish is one of the Arayos mentioned in the Torah, and thus it is included in the Mishnah's statement about a girl who has relations with "any one of the Arayos mentioned in the Torah."
Tosfos answers that had the Mishnah taught only that a girl who has relations with "any one of the Arayos mentioned in the Torah" is Chayav Misah (together with the man), we would not have included animals in that law because it refers only to relations between humans. When the Mishnah repeats the law that a man who has relations with a married three-year-old girl is Chayav Misah, it is hinting that the statement about "any one of the Arayos mentioned in the Torah" includes animals.
For this reason, the Mishnah there does not need to mention explicitly that an animal that has relations with a three-year-old girl is put to death.
In contrast, in the Mishnah here regarding the Bi'ah of a nine-year-old boy, no law is repeated. There is no repetition regarding adultery. Therefore, it is necessary to specify the law of relations with an animal explicitly, since the law is not included in the law regarding other Arayos.
(b) The VILNA GA'ON in ELIYAHU RABAH on the Mishnah points out that the Gemara in Sanhedrin gives two reasons for why the animal must be put to death. It must be put to death either because it caused the death of a person by necessitating that he be punished ("Takalah"), or because of the embarrassment that it causes the person every time anyone sees the animal ("Kalon"). These reasons apply whether the act was intentional or unintentional (Mezid or Shogeg). If one was forced (Ones) to do the act, then the animal is not put to death because there is no Takalah and no Kalon. (Since a forced act is not punishable with death, there is no Takalah. Since the person did not willingly sin, there is no embarrassment.)
However, the Gemara in Yevamos (33b) explains that a girl who is seduced is considered "forced." She is easily overtaken by physical sensations, and thus she does not have full control of her decision. A boy, in contrast, does not have the same physical sensations ("Ein Kishuy Ela l'Da'as" -- a male must consciously arouse himself.) When a boy sins with an animal, he is considered either Mezid or Shogeg, but not Ones, and at least the reason of Kalon applies, necessitating the death of the animal. When a girl sins with an animal, she is considered to be forced; there is no Takalah or Kalon, and thus the animal is not killed.
(The Vilna Ga'on adds that whether or not the animal is killed might depend on the girl's actions during the sin. The Gemara in Sanhedrin may be referring to a girl who had no physical sensations before the act. Since she aroused herself, there is Kalon, and thus the animal must be killed.)
(c) The RA'AVAD differentiates between the animal's status as Chayav Misah and the animal's status as forbidden to the Mizbe'ach. In a case in which only one person witnessed the act, the animal is not killed. Nevertheless, the animal is unfit for the Mizbe'ach, because a foul act was committed with it. (It becomes "Ma'us," or disgusting, to be offered on the Mizbe'ach.)
If the animal derives pleasure from the sin, then it is considered "Ma'us." An animal does not derive pleasure from the act with a boy younger than nine years old, who is not Mazri'a. Only when the animal has relations with a boy older than nine does the animal become Chayav Misah and unfit for the Mizbe'ach. In contrast, an animal that sins with a girl derives the same degree of pleasure whether she is above the age of three or not. When the girl is below the age of three, the animal is not killed (because the act is not considered Bi'ah), but it becomes unfit for the Mizbe'ach because a disgusting act nonetheless was done.
Accordingly, the Mishnah does not mention the law that the animal becomes unfit for the Mizbe'ach when it has relations with a three-year-old girl, because the age of three does not affect that law! Since there is no need to mention this Halachah with regard to a three-year-old girl, the law of killing the animal is also omitted (and only in Sanhedrin does the Gemara derive the Halachah that the animal must be killed).

45b----------------------------------------45b

2) A GIRL WHO MAKES A "NEDER" IN HER TWELFTH YEAR
QUESTION: The Mishnah teaches that when a girl who is eleven years and one day old makes a Neder, we assess her to determine if she knows for Whom she made the Neder (Rashi DH Nivdakin). If she is intellectually mature enough to make her Neder for Hash-m, then her Neder is binding. When a girl who is twelve years and one day old makes a Neder, it takes effect immediately. During her twelfth year (between the ages of eleven and twelve), we must assess her to determine if she knows for Whom she made the Neder.
The Gemara explains that although the Mishnah says that a girl's Neder is valid at the age of twelve years and one day, which implies that before that age (during the twelfth year) her Neder is not valid without determining her intellectual maturity, it is necessary for the Mishnah to articulate the latter Halachah. One might have thought that the Neder of a girl who is eleven years and one month old is binding without needing to check her, even when she was checked during the first month of that year and found not to know for Whom she makes a Neder. There is a principle that "thirty days in a year is considered a full year," and thus at the age of eleven years and one month she is considered a twelve-year-old. Therefore, the Mishnah states clearly that she must be assessed throughout the entire twelfth year.
The Gemara's explanation is not clear. It should be obvious that we must assess the girl's intellectual maturity when she makes a Neder after the age of eleven years and one month, and the Mishnah should not need to teach this. Even though she was checked before and found not to be intellectually mature, there is no reason to assume that she will remain intellectually immature (as the verse in Iyov (32:7) says, "The many days will teach her wisdom"), and thus we certainly should have to check her throughout the entire twelfth year. (See BACH YD 233:1, DH Katan.)
ANSWER: The CHOCHMAS BETZALEL (Pischei Nidah) answers based on the words of RASHI (DH Su Lo). Rashi writes, "veli'Chazkah b'Ketanah" -- we should assume that her status with regard to making a Neder remains the same as it was until now, when she was a Ketanah. Rashi means that since, until now, we knew that she was a minor whose Nedarim are not valid, we might have assumed that until we know otherwise, her status did not change. This is similar to the Torah's law to follow the Chazakah in cases of doubt (see Chulin 10b), even when the outcome might be a leniency (such as in this case, where we would say that the girl's Neder does not take effect). The Mishnah is teaching that in this case, we do not rely on the Chazakah and we must check the girl's Nedarim throughout the entire twelfth year.
The PISCHEI NIDAH gives several reasons for why we do not rely on the Chazakah in this case:
1. The MAGEN AVRAHAM (OC 8:11) writes that we do not rely on a Chazakah when it is possible to check if the situation has changed. (For this reason, he explains that one should examine one's Tzitzis every morning to ensure that none of the strings have torn, even though there is a Chazakah that the strings are still fit.) Since it is possible to check if the girl knows for Whom she made her Neder, we must check and we may not rely on the Chazakah. (The Pischei Nidah cites support for the Magen Avraham's ruling from TOSFOS in Bava Basra 156a, DH ul'Gerushin.)
2. The Magen Avraham elsewhere (OC 437:4) writes that only when there is a counter Chazakah of Isur are we required to check (when possible) and not rely on the Chazakah of Heter. (For this reason, when one rents a house from another Jew on Erev Pesach, he must ask the owner whether he searched for Chametz, even though there is a Chazakah that he already searched (since the Halachah requires him to search), because there is a counter Chazakah that the house was full of Chametz throughout the rest of the year.) Why, then, do we not rely on the Chazakah of the girl in this case? What counter Chazakah says that she knows to Whom she makes a Neder? The Pischei Nidah explains that the Chazakah of Isur in this case is that it is common for girls in the year before adulthood to know to Whom they make Nedarim. (See DAGUL MEREVAVAH to Magen Avraham (OC 8:11), who discusses an apparent contradiction in the words of the Magen Avraham in these two places.)
3. A Neder is considered a "Davar she'Yesh Lo Matirin," an Isur that can become permitted (through the nullification of a Chacham). The Gemara in Beitzah (4a) says in the name of Rav Ashi that in the case of a "Davar she'Yesh Lo Matirin," we must be stringent even for a doubt in an Isur d'Rabanan. Therefore, we check the girl's Nedarim even though there is a Chazakah. (D. BLOOM)
3) THE DIFFERENCE BETWEEN THE AGES OF MALE AND FEMALE MATURITY
OPINIONS: The Mishnah teaches that a girl reaches maturity at the age of twelve. The Gemara explains that this follows the view of Rebbi, who maintains that Hash-m gave more understanding (Binah) to women than men.
In what way does this make women mature earlier than men?
(a) The TOSFOS HA'ROSH explains that this means that Hash-m gives Binah to women earlier than He gives Binah to men. Hence, women are considered to mature earlier because their mental capacity develops at a younger age.
(b) The RAMBAM (in Perush ha'Mishnayos) explains that women mature earlier physically, and not just mentally, and they age faster than men (they have a shorter lifespan), and thus they also reach maturity sooner.
(c) The ROSH (Teshuvos #16) explains that all of the Halachic indications of maturity are Halachos l'Moshe mi'Sinai, and thus there is no obvious, rational reason to explain why women reach maturity earlier than men.

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